Fuse and fuse puller



Emma 2, 193%. 5 000 2,042,75g

FUSE AND FUSE FULLER Filed Aug. 31, 1934 Patented June 2, 1936 UNITED STATES PATENT OFFICE The Chase-Shawmut Company,

Newburyport,

Mass., a corporation of Massachusetts Application August 31, 1934, Serial No. 742,248 2 Claims. (01. 200-113) This invention relates to electric fuses and particularly to electric fuses of the cartridge type which have end caps or ferrules on the ends of an insulating tube that contains the fusible element, the end caps or ferrules constituting the terminals of the fuse.

This type of fuse is supported removably in circuit controlling position by resilient fuse clips end caps and are electrically included in the circuit the fuse is intended The fuse clips are approximately as broad as the end caps are long and are spaced about the same distance apart as are the end caps. With fuses of the smaller capacities this distance is relatively short. The fuses are usually removed from their retaining clips by grasping the the fuse between the thumb and finger of a hand and pulling the 'fuse out of the clips. Due to the short spacing between the end caps and between the fuse clips considerable care has to be exercised in avoiding contact with an end cap or fuse clip when removing a fuse as contact with a fuse clip or end cap may result in an electrical shock. Furthermore these fuses are usually arranged in gangs of two or three or more disposed in such close relation on a base that it is difficult to grasp one fuse without having the fingers come in contact with the end cap or fuse clip of an adjacent fuse.

Hence an object of the present invention is the provision of a shield for a cartridge type fuse, and a fuse so equipped, the shield having insulating portions disposed adjacent the fuse clips and the inner ends of the end caps and outstanding r from the fuse and constituting insulating barriers interposed between the live parts and the body of the fuse which prevent accidental contact of the fingers with a fuse clip during the. act of removing the fuse from the clip.

Since the spacing between the supporting clips of a fuse, and between the several fuses on a base is so close, usually, that it is awkward to remove the fuses a further object of the invention is an improved form of fuse puller that is adapted to engage the fuse and have a part that projects upwardly above the fuse a sufiicient distance to enable it to be gripped freely by the fingers and pulled to remove the fuse from the clips.

A further object of the invention is in providing the fuse puller with the insulating clip shields above described.

The fuse puller embodying the present invention is adapted both for the so-called one-time fuse and also the renewable fuse, both of which have cylindrical end caps which are larger in diameter than the insulating tubular body of the fuse. It is an object of the present invention to provide a fuse puller having relatively inclined end portions adapted to be disposed loosely on the insulating body of the fuse adjacent the inner ends of the end caps, the end portions having apertures therethrough that are about equal to or only slightly greater in diameter than the diameter of the end caps so that the end caps through the apertures readily and A further object of the invention is the provision of a fuse puller composed of one piece of a suitable cheap insulating material that can be packaged in flat form and subsequently bent into shape in a manner that will be obvious to the user and placed on the fuse.

The fuse puller and clip shield embodying the present invention is composed of one piece of moderately stiff yet flexible insulating sheet material as fibre having two disc shaped end portions connected by a reduced body portion or neck, the disc shaped portions having apertures therethrough in which the fuse is loosely received and constituting clip shields and the neck constituting a handle. Such a device constitutes a further object of the invention.

A yet further object of the invention is generally to improve the construction of fuse pullers.

Fig. 1 is an end elevation of a fuse base having fuses provided with the fuse puller and clip shield embodying the present invention.

Fig. 2 is a side elevation of Fig. 1.

Fig. 3 is a side elevation of av fuse and fuse puller with the fuse puller shown partly in section.

Fig. 4 is a section taken along line 4-4 of Fig. 2.

Fig. 5 is a plan view of the fuse puller.

Fig. 6 is a section taken along line 6-6 of Fig. 5.

Fig. 7 is a view illustrating the manner of applying the device to a cartridge fuse.

The present invention is especially adapted for cartridge type fuses havi g a tubular insulating enclosing casing I0 provided with cylindrical end caps or ferrules l2 which for a one-time fuse are permanently secured to the ends of the casing l0 and for a renewable fuse are removably attached to, as screw-threaded on, the ends of the casing. The cartridge fuse in its service position is carried by a fuse base I4 having spring clips l6 that are connected in the circuit protected by the fuse and are spaced apart by approximately the spacing of the end caps and are approximately as "can be disposed on end caps accidentally.

broad as the end caps are long. The length of the insulating portion of the fuse casing between the end caps and the spacing between the fuse clips is relatively short so that care has to be exercised to avoid contact with the end caps or fuse clip when the insulating casing is grasped by the fingers to remove the fuse from the clips. Usually also two or. more fuses are arranged in side by side relation on a common supporting base, as illustrated in Fig. 1. The spacing between the fuses also is relatively short so that? care has to be exercised when one fuse is grasped for removing it, that the fingers do? not come in contact with the fuse clip or other. live part associated with an adjacent fuse.

In accordance with the present invention 'I have provided a fuse puller adaptedto facilitate the removal of the fuses from and also their insertion in the fuse clips and at the same time pro-- that are inte'rposedbe viding insulating shields tween the fuse clips or other current conducting parts associated with the fuses and the fingers. Said fuse puller, illustrated by itself in Figs. 5 and 6, is formed from a fiat sheet of suitable insulating material as fibre and the like of suitable flexibility to be flexed into V-shape by the user of the device, and yet sufficiently stiff to be rigid in its bent form when subjected to pressure thereon in a direction to insert the fuse in its clips and strong enough to withstand repeated use. The fuse puller is formed with two disc shaped end portions l8 connected by a body portion or neck 20. The end portions have centrally located circular apertures 22 therein which are approximately as large as or only slightly greater than the diameter of the end caps i2 of the fuse with which the puller is associated. The essential requirements as to diameter of the apertures 22 is that the diameter shall be large enough to permit the end cap to be pushed readily therethrough by the fingers so that the end portions the body portion Ii] of the fuse, the diameter of which is considerably smaller than the diameter of the apertures 22 so that when the fuse puller is in position it is loose on the fuse. The fuse puller is adapted to be bent into a general V-shape, as illustrated in Figs. 2 and 3, with the legs i8a of the puller inclined away from each other. With this arrangement the projected diameter of the apertures 22 is less than the diameter of the end caps so that the inclined ends of the puller can not slip over the The V-shaped puller is somewhat resilient and the inclined legs iBa have an inherent tendency to spread apart but are limited in their outward movement by engagement with the inner ends of the end caps. The puller, however, can readily be removed from the fuse when desired, and applied to the fuse, by positioning an 'end portion l8 perpendicular to the fuse and sliding it over the end cap by the pressure of the fingers thereon inthe manner illustrated in Fig. '7. The body portion or neck of the puller is made suitably smaller in width than the diameter of the end I8 so that the neck can be conveniently grasped between a thumb and finger and used as a handle for inserting the fuse in and withdrawing it from its fuse clips. The puller is sufficiently stiff to resist the pressure required to push the fuse into the fuse clips. The ends l8 are considerably larger in diameter than the diameter of the fuse passages 22 therein so that the ends stand outwardly from the fuse beyond the projecting parts of the fuse clip sufficiently so that there is little chance for the fingers to come in contact with the fuse clips in the act of inserting or removing the fuse. The ends H3 thus constitute clip shields that are in- I terposed between the end caps and the fuse clips and the finger space therebetween. The diameter or width of the ends l8 of the puller is also sufliciently great so that the ends of the pullers on adjacent fuses on a fuse base constitute a practically continuous barrier, as illustrated in Fig. 1, between the finger space of a puller and the fuse clips of an adjacent fuse so that the act of inserting or removing a fuse can be accomplished without danger of inadvertently bringin'g the fingers in contact with the live part associated with an adjacent fuse.

The fuse puller herein described is intended primarily to be packaged in the flat form illustrated in Figs. 5 and 6, and bent into shape and installed by the fuse user, the length of the puller being such that the act of placing the ends thereof on the fuse necessarily bends it into the proper shape. The fuse puller is effective in use and is cheapto manufacture.

I claim':

1. A fuse puller comprising a fiat strip of electrically insulating material having at each end an aperture in bcth of which a cartridge type fuse is adapted to be received when the strip is refiexed transversely of its length between its ends, the ends of the strip being materially wider than the diameter of the apertures so that they outstand materially beyond the fuse clips in which the end caps of the fuse are received when the fuse is in use whereby to constitute insulating barriers that are interposed between the fuse clips and the fingers.

' 2. A fuse puller comprising an electrically in- 

